Restrictive versus Liberal Fluid Therapy for Major Abdominal Surgery

BACKGROUND

Guidelines to promote the early recovery of patients undergoing major surgery recommend a restrictive intravenous-fluid strategy for abdominal surgery. However, the supporting evidence is limited, and there is concern about impaired organ perfusion.

METHODS

In a pragmatic, international trial, we randomly assigned 3000 patients who had an increased risk of complications while undergoing major abdominal surgery to receive a restrictive or liberal intravenous-fluid regimen during and up to 24 hours after surgery. The primary outcome was disability-free survival at 1 year. Key secondary outcomes were acute kidney injury at 30 days, renal-replacement therapy at 90 days, and a composite of septic complications, surgical-site infection, or death.

RESULTS

During and up to 24 hours after surgery, 1490 patients in the restrictive fluid group had a median intravenous-fluid intake of 3.7 liters (interquartile range, 2.9 to 4.9), as compared with 6.1 liters (interquartile range, 5.0 to 7.4) in 1493 patients in the liberal fluid group (P<0.001). The rate of disability-free survival at 1 year was 81.9% in the restrictive fluid group and 82.3% in the liberal fluid group (hazard ratio for death or disability, 1.05; 95% confidence interval, 0.88 to 1.24; P=0.61). The rate of acute kidney injury was 8.6% in the restrictive fluid group and 5.0% in the liberal fluid group (P<0.001). The rate of septic complications or death was 21.8% in the restrictive fluid group and 19.8% in the liberal fluid group (P=0.19); rates of surgical-site infection (16.5% vs. 13.6%, P=0.02) and renal-replacement therapy (0.9% vs. 0.3%, P=0.048) were higher in the restrictive fluid group, but the between-group difference was not significant after adjustment for multiple testing.

CONCLUSIONS

Among patients at increased risk for complications during major abdominal surgery, a restrictive fluid regimen was not associated with a higher rate of disability-free survival than a liberal fluid regimen and was associated with a higher rate of acute kidney injury. (Funded by the Australian National Health and Medical Research Council and others; RELIEF ClinicalTrials.gov number, NCT01424150 .).

Beneficial Effects of Pet Ownership on Some Aspects of Human Health and Behaviour

A 10-month prospective study was carried out which examined changes in behaviour and health status in 71 adult subjects following the acquisition of a new pet (either dogs or cats). A group of 26 subjects without pets served as a comparison over the same period. Both pet-owning groups reported a highly significant reduction in minor health problems during the first month following pet acquisition, and this effect was sustained in dog owners through to 10 months. The pet-acquiring groups also showed improvements in their scores on the 30-item General Health Questionnaire over the first 6 months and, in dog owners, this improvement was maintained until 10 months. In addition, dog owners took considerably more physical exercise while walking their dogs than the other two groups, and this effect continued throughout the period of study. The group without pets exhibited no statistically significant changes in health or behaviour, apart from a small increase in recreational walking. The results provide evidence that pet acquisition may have positive effects on human health and behaviour, and that in some cases these effects are relatively long term.

Surgical management of the recurrent laryngeal nerve in thyroidectomy: American Head and Neck Society Consensus Statement

"I have noticed in operations of this kind, which I have seen performed by others upon the living, and in a number of excisions, which I have myself performed on the dead body, that most of the difficulty in the separation of the tumor has occurred in the region of these ligaments…. This difficulty, I believe, to be a very frequent source of that accident, which so commonly occurs in removal of goiter, I mean division of the recurrent laryngeal nerve." Sir James Berry (1887).

Safety and Efficacy of Isolated Limb Infusion Chemotherapy for Advanced Locoregional Melanoma in Elderly Patients: An Australian Multicenter Study

BACKGROUND

Isolated limb infusion (ILI) offers a minimally invasive treatment option for locally advanced extremity melanoma.

OBJECTIVE

The aim of the current study was to evaluate the safety and efficacy of ILI in elderly patients in an Australian multicenter setting.

METHODS

The results of 316 first ILI procedures, performed between 1992 and 2008 in five Australian institutions, were identified and analyzed, with the main focus on elderly patients (≥75 years of age). All institutions used the same protocol: melphalan was circulated in the isolated limb for 20-30 min (±actinomycin D), and toxicity, responses, and survival were recorded.

RESULTS

Characteristics of patients aged ≥75 years (n = 148) were similar to those aged <75 years (n = 168), except that older patients had more melanoma deposits (median 4 vs. 5; p = 0.035) and lower limb volumes (5.4 vs. 6.5 L; p = 0.001). Median drug circulation times were lower in the older group (21 vs. 24 min; p = 0.04), and older patients experienced less limb toxicity (grade III/IV in 22 and 37% of patients, respectively; p = 0.003). A complete response (CR) was seen in 27% of patients aged ≥75 years and in 38% of patients aged <75 years (p = 0.06), while overall response rates were 72 and 77%, respectively (p = 0.30). No difference in survival was seen (p = 0.69).

CONCLUSIONS

The ILI technique proved safe and effective in elderly patients. When present, toxicity was localized, and lower compared with younger patients, possibly due to shorter drug circulation times. CR rates were higher in younger patients, although not significantly, while overall response and survival were equal. Optimization of perioperative factors in elderly patients may allow response rates to be raised further, while maintaining low toxicity.

Total thyroidectomy for pressure symptoms in patients with Hashimoto's thyroiditis

BACKGROUND

Hashimoto's thyroiditis (HT) is rarely on its own the indication for thyroidectomy. However, surgery in patients with HT will be undertaken when there is malignancy and may be required for pressure symptoms. Therefore, this study aimed to investigate the indications for surgery in HT patients.

METHODS

The Monash University Endocrine Surgery Database was analysed from 1994 to 2013 for patients with HT. Patients with HT were compared to a similar group of patients with no HT on histopathology. Patient demographics, indication for surgery, histopathology, gland weight and complications were analysed.

RESULTS

A total of 2346 patients underwent total thyroidectomy during the study period. The median age was 55 years. Eleven percent of patients had HT on final pathology (259/2346). HT patients reported more pressure symptoms, 25.5% compared to those with other pathology, 18.9% (P = 0.01). Patients with pressure symptoms had heavier glands, 113 g compared to 85 g in those with other indications for surgery (P = 0.048). Within the HT cohort, the median gland weight was 66 g compared to 93 g in those without HT (P < 0.01). On multivariate analysis, pressure symptoms as an indication for surgery was associated with HT (P < 0.01), but age, gender and gland weight were not associated. In patients operated for pressure with HT as the only pathology, 90% had relief of pressure symptoms.

CONCLUSION

Patients with HT were more likely to have pressure symptoms as an indication for surgery independent of gland weights.

Restrictive versus liberal fluid therapy in major abdominal surgery (RELIEF): rationale and design for a multicentre randomised trial

INTRODUCTION

The optimal intravenous fluid regimen for patients undergoing major abdominal surgery is unclear. However, results from many small studies suggest a restrictive regimen may lead to better outcomes. A large, definitive clinical trial evaluating perioperative fluid replacement in major abdominal surgery, therefore, is required.

METHODS/ANALYSIS

We designed a pragmatic, multicentre, randomised, controlled trial (the RELIEF trial). A total of 3000 patients were enrolled in this study and randomly allocated to a restrictive or liberal fluid regimen in a 1:1 ratio, stratified by centre and planned critical care admission. The expected fluid volumes in the first 24 hour from the start of surgery in restrictive and liberal groups were ≤3.0 L and ≥5.4 L, respectively. Patient enrolment is complete, and follow-up for the primary end point is ongoing. The primary outcome is disability-free survival at 1 year after surgery, with disability defined as a persistent (at least 6 months) reduction in functional status using the 12-item version of the World Health Organisation Disability Assessment Schedule.

ETHICS/DISSEMINATION

The RELIEF trial has been approved by the responsible ethics committees of all participating sites. Participant recruitment began in March 2013 and was completed in August 2016, and 1-year follow-up will conclude in August 2017. Publication of the results of the RELIEF trial is anticipated in early 2018.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov identifier NCT01424150.

Temporal analysis of thyroid cancer management in a Melbourne tertiary centre

BACKGROUND

The American Thyroid Association (ATA) management guidelines for thyroid cancer were revised in 2009. The aim of this study was to determine if management of thyroid cancer in our institution has changed in accordance with the introduction of the revised ATA guidelines (ATA²⁰⁰⁹ ), and to compare the characteristics and management of thyroid cancer in a Melbourne endocrine surgery unit over a 7-year period.

METHODS

All patients treated by the Monash University Endocrine Surgery Unit for thyroid cancer between 2007 and 2013 were divided into two groups - the pre-ATA²⁰⁰⁹ group (2007-2010) and the post-ATA²⁰⁰⁹ group (2011-2013). Comparisons were made of the demographics, cytology, pathology, surgical outcome and adjuvant therapy using t-test and chi-squared tests.

RESULTS

There were 333 patients in the pre-ATA²⁰⁰⁹ group and 342 patients in the post-ATA²⁰⁰⁹ group. Fewer non-diagnostic fine-needle aspiration cytology results were identified in the post-ATA²⁰⁰⁹ group (4% versus 0.9%; P = 0.01), while the rates of other fine-needle aspiration cytology categories were similar. There was a reduction in the use of radioactive iodine ablation in the post-ATA²⁰⁰⁹ group, both in the proportion of patients being treated (66% versus 48%; P < 0.001) and the dosages used (mean 96 mCi versus 80 mCi; P < 0.01), despite similar tumour size in both groups.

CONCLUSION

The key changes in practice thought to be attributable to the 2009 revised ATA guidelines were the reduction in the use and dosage of radioactive iodine in the management of differentiated thyroid cancer.

Surgery for parathyroid microadenomas: patient characteristics, localization success and operative cures

BACKGROUND

In recent years, patients with primary hyperparathyroidism (PHPT) are being diagnosed earlier, with milder elevations in parathyroid hormone (PTH) and serum calcium. We aimed to investigate whether adenoma size reflects biochemical severity of presentation and influences localization of pre-operative scans.

METHODS

A total of 630 consecutive patients undergoing parathyroidectomy for PHPT were recruited into either the microadenoma (≤200 mg) or macroadenoma (>200 mg) group. Pre-operative serum calcium, PTH, rates of minimally invasive parathyroidectomy and bilateral neck exploration, localization of adenomas with pre-operative ultrasound and sestamibi (MIBI) scans, cure rates and other demographic parameters were compared. The data were analysed using Student's t-test, Chi-squared test, linear and multiple regression analyses.

RESULTS

Patients in the microadenoma group had significantly lower pre-operative serum calcium (P < 0.001) and PTH (P < 0.001), less accurate MIBI (P < 0.001) and ultrasound (P < 0.001), lower cure rates (P = 0.04) and were more likely to undergo bilateral neck exploration (P = 0.001). However, multivariate analysis revealed that microadenomas are most strongly associated with the findings of less accurate MIBI (P = 0.03) and lower pre-operative calcium (P = 0.04).

CONCLUSION

In conclusion, smaller adenomas are strongly associated with biochemically milder PHPT and less accurate localization studies. Therefore, microadenomas continue to present as a challenge in both diagnosis and management.

The Effect of Routine Reversal of Neuromuscular Blockade on Adequacy of Recurrent Laryngeal Nerve Stimulation during Thyroid Surgery

Testing of the integrity of the recurrent laryngeal nerve during thyroid surgery has become routine practice for many surgeons to aid dissection and minimise the chance of inadvertent nerve injury. We hypothesised that routine reversal of an intermediate-acting, non-depolarising neuromuscular blocking agent would improve conditions for stimulation of the recurrent laryngeal nerve. We conducted a single-centre, randomised, double-blind placebo-controlled trial of patients undergoing thyroid surgery by the same surgeon. After randomisation, the participants received either neostigmine 2.5 mg with glycopyrrolate 0.4 mg or placebo, at 30 minutes after induction of anaesthesia and administration of 0.4 mg/kg of atracurium. The primary outcome was the subjective assessment by the surgeon as to whether the neuromuscular function was adequate for stimulation of the recurrent laryngeal nerve using a neuromuscular integrity monitor (NIM). Time to NIM stimulation was 44.6 minutes in the placebo group and 41.4 minutes in the intervention group ( P=0.268). Of the 21 patients who received the neuromuscular blockade reversal, 20 (95.2%) had adequate surgical conditions for NIM stimulation, compared to 9 out of 18 patients (50%) in the placebo group ( P=0.002). Three of the ten patients (30%) with inadequate reversal showed no evidence of residual blockade assessed peripherally. The routine reversal of neuromuscular blockade at 30 minutes post induction appears to result in adequate surgical conditions for safe stimulation of the recurrent laryngeal nerve. Return of neuromuscular function at a peripheral site does not guarantee adequate laryngeal muscle function for use of the NIM.

Papillary thyroid cancer-derived exosomes contain miRNA-146b and miRNA-222

BACKGROUND

With the increasing diagnosis of indolent papillary thyroid cancer (PTC), the task of identifying those likely to suffer from recurrence is becoming ever more challenging. MicroRNA (miRNA/miR) in the circulation has been demonstrated as potential biomarkers of recurrence in PTC. This study aimed to investigate in vitro if extracellular miRNAs are contained in exosomes, and their potential effect on other cells.

METHODS

TPC-1 (PTC) and NTHY (normal thyroid follicular) cell lines were treated with exosome isolates and conditioned medium (CM), both containing miR-146b and miR-222. The changes in proliferation over a 72-h period of TPC-1 and NTHY were compared. Student t-test and analysis of variance were used for significance testing, and P < 0.05 was considered significant.

RESULTS

Exosomes derived from TPC-1 cells were demonstrated to contain miR-146b and miR-222 in relative abundance. These exosomes caused a negative proliferative effect on both TPC-1 and NTHY cells. Exosomes derived from NTHY cells did not exert a significant proliferative effect on either cell line. CM from both cell types caused an initial increase in TPC-1 proliferation at 24 h. No significant change in proliferation was seen with NTHY cells when treated with either of the CM.

CONCLUSIONS

The results showed that PTC cells overexpress miR-146b and miR-222 in exosomes; and that factors released by both normal thyroid and PTC cells alter proliferation of other cells in a complex manner. The intercellular interactions were likely conferred in part by exosomal miRNA, which can potentially be developed as biomarkers of PTC recurrence.

Noncoding RNA blockade of autophagy is therapeutic in medullary thyroid cancer

Micro-RNAs are dysregulated in medullary thyroid carcinoma (MTC) and preliminary studies have shown that miRNAs may enact a therapeutic effect through changes in autophagic flux. Our aim was to study the in vitro effect of miR-9-3p on MTC cell viability, autophagy and to investigate the mRNA autophagy gene profile of sporadic versus hereditary MTC. The therapeutic role of miR-9-3p was investigated in vitro using human MTC cell lines (TT and MZ-CRC-1 cells), cell viability assays, and functional mechanism studies with a focus on cell cycle, apoptosis, and autophagy. Post-miR-9-3p transfection mRNA profiling of cell lines was performed using a customized, quantitative RT-PCR gene array card. This card was also run on clinical tumor samples (sporadic: n = 6; hereditary: n = 6) and correlated with clinical data. Mir-9-3p transfection resulted in reduced in vitro cell viability; an effect mediated through autophagy inhibition. This was accompanied by evidence of G2 arrest in the TT cell line and increased apoptosis in both cell lines. Atg5 was validated as a predicted miR-9-3p mRNA target in TT cells. Post-miR-9-3p transfection array studies showed a significant global decline in autophagy gene expression (most notably in PIK3C3, mTOR, and LAMP-1). Autophagy gene mRNAs were generally overexpressed in sporadic (vs. hereditary MTC) and Beclin-1 overexpression was shown to correlate with residual disease. Autophagy is a tumor cell survival mechanism in MTC that when disabled, is of therapeutic advantage. Beclin-1 expression may be a useful prognostic biomarker of aggressive disease.

A Cohort and Database Study of Airway Management in Patients Undergoing Thyroidectomy for Retrosternal Goitre

Patients undergoing thyroid surgery with retrosternal goitre may raise concerns for the anaesthetist, especially airway management. We reviewed a multicentre prospective thyroid surgery database and extracted data for those patients with retrosternal goitre. Additionally, we reviewed the anaesthetic charts of patients with retrosternal goitre at our institution to identify the anaesthetic induction technique and airway management. Of 4572 patients in the database, 919 (20%) had a retrosternal goitre. Two cases of early postoperative tracheomalacia were reported, one in the retrosternal group. Despite some very large goitres, no patient required tracheostomy or cardiopulmonary bypass and there were no perioperative deaths. In the subset of 133 patients managed at our institution over six years, there were no major adverse anaesthetic outcomes and no patient had a failed airway or tracheomalacia. In the latter cohort, of 32 (24%) patients identified as having a potentially difficult airway, 17 underwent awake fibreoptic tracheal intubation, but two of these were abandoned and converted to intravenous induction and general anaesthesia. Eleven had inhalational induction; two of these were also abandoned and converted to intravenous induction and general anaesthesia. Of those suspected as having a difficult airway, 28 (87.5%) subsequently had direct laryngoscopy where the laryngeal inlet was clearly visible. We found no good evidence that thyroid surgery patients with retrosternal goitre, with or without symptoms and signs of tracheal compression, present the experienced anaesthetist with an airway that cannot be managed using conventional techniques. This does not preclude the need for multidisciplinary discussion and planning.

MicroRNA expression profiles in the management of papillary thyroid cancer

Papillary thyroid cancer (PTC) is the major contributor to the dramatically increasing incidence of thyroid cancer. Low-risk PTC shows the most rapid rate of increase because of changing trends in neck imaging and the use of fine needle aspiration to investigate thyroid nodules. The need for a paradigm shift in the management of these patients, to provide personalized treatment and surveillance plans, has led to the focus on molecular biomarker research. MicroRNAs (miRNAs) compose a class of molecules with promising applications for every stage of PTC management, including diagnosis, prognosis, treatment, and surveillance. Although most of the miRNA studies are currently preclinical, given the rapid progress of scientific discovery, clinical trials will not be far away. Thyroid clinicians will be expected to have good insights into the current status of PTC-related molecular translational research. This article focuses on the potential roles of miRNA in PTC management in the context of contemporary recommended clinical practice.

Australian multi-center experience outside of the Sydney Melanoma Unit of isolated limb infusion chemotherapy for melanoma

INTRODUCTION

Isolated limb infusion (ILI) is a minimally invasive alternative to isolated limb perfusion (ILP) for delivering high-dose regional chemotherapy to treat locally advanced limb melanoma. The current study aimed to evaluate the applicability of ILI in four Australian tertiary referral centers outside of its originating institution, the Sydney Melanoma Unit (SMU; currently known as the Melanoma Institute Australia).

METHODS

Data of 131 patients, treated between 1992 and 2008 were collectively analyzed. The ILI procedures were based on the Sydney Melanoma Unit protocol using melphalan. Response was determined using the WHO criteria and toxicity was assessed using the Wieberdink scale.

RESULTS

The median patient age was 74 years (range 28-100). Fifty-six percent were female. Overall response (OR) rate to ILI was 63% (CR 27%; PR 36%). Wieberdink toxicity grade III or higher was seen in 13%. No toxicity-related amputations occurred. Median follow-up was 24 months; median survival was 58 months. In patients with a complete response (CR), median survival was 101 months; in patients with a partial response (PR) this was 41 months (P = 0.026). On univariate analysis a younger age, lower-limb procedures and a lower Breslow thickness of the primary melanoma were associated with a favorable response. On multivariate analysis Breslow thickness and lower-limb ILI remained significant predictors for response.

CONCLUSION

In this, to date, largest multi-center study of ILI for melanoma the results are comparable to other reports and demonstrate that ILI can be widely implemented and safely applied across tertiary referral centers.

Perioperative complications in patients on low-molecular-weight heparin bridging therapy

BACKGROUND

Patients taking warfarin are often given interim anticoagulation in the perioperative period. Institutional guidelines that use low-molecular-weight heparin (LMWH) 'bridging' while the international normalized ratio (INR) is sub-therapeutic are often based on the American College of Chest Physicians Anticoagulation Guidelines.

PURPOSE

This study aims to identify if patients at a tertiary referral hospital were anticoagulated in line with these guidelines, and the incidence and nature of bleeding and thromboembolic complications.

METHODS

A retrospective review of the Alfred Hospital General Surgical and 'Hospital at Home' databases was conducted, identifying patients who underwent elective general surgical procedures and received bridging anticoagulation with enoxaparin. Demographics, indication for anticoagulation, bleeding and thromboembolism rates were recorded. Thromboembolic risk was estimated.

RESULTS

The study identified 108 patients. Three-quarters of all patients were anticoagulated with LMWH doses in accordance with the guidelines. Thirty of the 108 patients suffered bleeding complications. This group was younger, weighed less, received higher doses of enoxaparin and were at higher predicted risk of thromboembolism than non-bleeding patients. Wound haematoma, rectal bleeding and intra-abdominal bleeding were the most frequent complications. The peak time of bleeding was 3.5 days after surgery. Twelve patients returned to theatre, 13 were readmitted and 3 received blood transfusion. One patient suffered pulmonary emboli on the first post-operative day.

CONCLUSION

LMWH bridging therapy when prescribed appropriately is associated with low rates of inpatient thromboembolism in elective general surgical patients within our institution, but an unexpectedly high rate of bleeding complications.

Adenomas of cervical maldescended parathyroid glands: pearls and pitfalls

BACKGROUND

Missed parathyroid adenoma (PTA) is the commonest cause of persistent hyperparathyroidism. Although many are subsequently found in well-described locations, some are found in unusual regions of the neck. This paper presents the combined experience of three large tertiary endocrine surgery centres with maldescended PTA (MD-PTA).

METHODS

Patients were recruited from the endocrine surgical databases of three tertiary endocrine surgery units. Patients with PTA found >1 cm above the superior thyroid pole or other cervical locations as a result of abnormal or incomplete descent were included for analysis.

RESULTS

MD-PTA was identified in 16 patients out of a total of 5241 patients who had undergone parathyroidectomies in the 7-year study period (incidence 0.3%). Seven (44%) patients had minimally invasive parathyroidectomy, while nine (56%) had bilateral neck exploration. The mean excised gland weight was 750 + 170 mg. Cure was achieved in all patients with a minimum follow-up of 6 months. The locations of MD-PTA in this study included submandibular triangle, retropharyngeal space, carotid sheath (at carotid bifurcation and intravagal), parapharyngeal space (superior to thyroid cartilage or superior thyroid pole) and cricothyroid space.

CONCLUSIONS

Despite their rare occurrence, incompletely or abnormally descended PTAs can be encountered by any surgeon who performs parathyroidectomies. It is important to develop a strategy to systematically locate these glands. High cure rates can still be achieved with minimally invasive parathyroidectomy if confident preoperative localization is available. A sound knowledge of embryology and a thorough exploration also facilitate an overall high success rate with open exploration.